I've been trying to find an answer to this on stackoverflow for about an hour now, seems that a lot of similar problems are around but none really fitting to mine.
Information about what tools I'm using can be found further down!
I am writing my own compiler for a subset of the java language and thus creating assembler code. Now I'm at a point where I need to debug said assembler code to locate a bug. The problem is when I compile my assembler code to a binary with gcc -m32 -g myAssembler.s I get the following warning:
warning: no debug symbols in executable (-arch i386)
(This warning also occurs using -ggdb, -ggdb2, -ggdb3, -g2, -g3instead of -g
Since there are no debug symbols I can't use gdb to debug my code. I don't know much about linking and how it's done or who does it (especially on a Mac), so precise/noob-friendly answers would be very welcome.
Tools I'm using:
The assembly created from my compiler is x86, 32-bit GAS Syntax.
I am using OS X Mavericks with GNU gdb (GDB) 7.6 downloaded via MacPorts (They changed its name to ggdb. The ggdb --version command shows also a line saying :
This GDB was configured as "x86_64-apple-darwin13.0.0".
(Not quite sure if that's important.)
Running gcc --version returns:
Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/usr/include/c++/4.2.1
Apple LLVM version 5.0 (clang-500.2.79) (based on LLVM 3.3svn)
Target: x86_64-apple-darwin13.0.0
Thread model: posix
This is probably connected with Apple dropping support for GDB in Xcode 5 and you are using the version of gcc that comes with Xcode 5. You probably need to change compiler or debugger (to lldb)… you might look at llvm-gcc (which Xcode 5 also drops support for). Try www.llvm.org for a download. But that might be more trouble than using lldb (if your problem is indeed connected to Xcode 5's changes). Good luck! – CRD
I just downloaded gcc-4.2 from homebrew and that seems to work for lldb (which is still supported by Xcode 5 it seems). – Octoshape
Related
I'm developing some C/C++/Objective C static analysis utility which works with llvm bytecode files. Its basic idea is quite simple:
1. Utility executes clang/clang++ with arguments "-c -emit-llvm -femit-all-decls -g" to generate llvm bytecode file for tested source file.
2. If file was created it's being read by LLVM C bindings and checked. Problems related to some specific code points are reported with source references since there are debug metadata with source references.
I've had a prototype of my utility which worked fine, but recently I've updated Xcode to 6.1 and source references became missing.
To fix this I've tried to rebuild my tool and llvm static libraries with updated compiler, but it didn't solved my problem.
I've tried to receive any hints from llvm, and the only thing I finally got is:
➜ bin ./llvm-dis test.bc
warning: ignoring debug info with an invalid version (600054001) in test.bc
So llvm-dis has shown me above warning and produced test.ll file which was stripped of any debug metadata attributes.
This is my simple test source file which I'm playing with:
int returnFive() {
return 5;
}
and some info which may be helpful:
➜ bin clang --version
Apple LLVM version 6.0 (clang-600.0.54) (based on LLVM 3.5svn)
Target: x86_64-apple-darwin14.0.0
Thread model: posix
➜ bin ./llvm-config --version
3.5.0
➜ bin ./llvm-config --host-target
x86_64-apple-darwin14.0.0
For me this seems very compatible, but it isn't so maybe someone can give me any suggestions on how to resolve this?
While I'm still not comfortable with the solution, I've hacked LLVM code and removed the call to llvm::UpgradeDebugInfo method from BitcodeReader::MaterializeModule code. Of course I may be punished for this if some truly incompatible LLVM compiler is used, but for now it works, furthermore not only clang from XCode can be used, but as well I can use Clang from LLVM release page which also produces "debug info with invalid version (0)".
After hours of research (and tries) on how to install id3lib on Qt (windows), but with no success, I decided to use TagLib's library.
I followed this tutorial to build a compatible version of taglib for Qt but still another problem (full log here):
...
C:\MinGW\bin\..\lib\gcc\mingw32\3.4.5\..\..\..\..\mingw32\bin\ld.exe: Dwarf
Error: found dwarf version '4', this reader only handles version 2 and 3
information.
C:/MinGW/bin/../lib/gcc/mingw32/3.4.5/../../../../mingw32/lib/crt2.o:crt1.c:(.text+0x1f1):
undefined reference to `__chkstk_ms'
...
In CMake, I did configure > MinGW Makefiles.
Can anyone tell how to fix it?
Environment:
Windows 7 (64-bit);
CMake 2.8.12.1;
TagLib 1.9.1;
GCC 3.4.5;
Qt 5.1.1.
The problem stems from the fact that you are using terribly outdated GCC, while your Qt binaries are most likely built with bleeding-edge GCC (or the one close to it). For instance, as the error message shows, DWARF is outdated in case of your current GCC and is incompatible with the one used by your current Qt. Furthermore, even if it wouldn't, you'd still hit other problems with binary incompatibilities, since you essentially mix compilers with different major version numbers, which is strongly discouraged. Notice, that your problem has nothing to do with CMake at all. You can see it yourself in the error message, i.e. the error is reported by ld, the linker utility from (your outdated) GCC toolchain. To conclude, your only option is to update GCC, ideally exactly to the one which was used to build your current Qt.
I typed this in my terminal:
llvm-gcc --version
But what I have is this :
Apple LLVM version 5.0 (clang-500.2.79) (based on LLVM 3.3svn)
Target: x86_64-apple-darwin13.0.0
Thread model: posix`
Am I not able to interpret this block of statements? or did I forget to enable something on my system?
Nothing is wrong. The situation is just a little confusing.
Apple no longer distributes GCC with Xcode. They now use Clang as the default (and only!) compiler on Mac OS X. cc, gcc, and clang (as well as the C++ variants, c++, g++, and clang++) are now all linked to run clang under current versions of Xcode.
The version of clang you're running is, per the --version output, 500.2.79.
If you want to install GCC as an alternative to clang, you can do so using a variety of methods, including one using Homebrew:
https://github.com/mxcl/homebrew/wiki/Custom-GCC-and-cross-compilers
For my studies I have to run a binary unix-program bomb with gdb.
Some time ago I followed the steps on http://jakoblaegdsmand.com/blog/2013/04/how-to-get-an-awesome-looking-terminal-on-mac-os-x/ and made some changes to my terminal-setup.
To runbomb with gdb I typed:
-> bomb207 gdb bomb
zsh: correct 'gdb' to 'gdv' [nyae]? n
zsh: command not found: gdb
When I type 'man gdb' zsh answers 'No manual entry for gdb'
How can I change my terminal-setup to support gdb?
ps.
I already installed the command line tools for os x with x code and I didn't had any problems until now...
bomb207 is the current directory and the location of bomb.
It appears that Apple (who have been switching from gcc to clang for some time) stopped including gdb in 10.8. Even in the CommandLine tools.
The clang debugger is lldb. It is similar in use to gdb, and I'm not finding it unduly difficult to switch. Aside from explaining to my finger that they shouldn't type gdb
for the debugger anymore: my fingers don't like change.
Yes, you can still type gcc to compile things, but look:
$ gcc --version
Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/usr/include/c++/4.2.1
Apple LLVM version 5.0 (clang-500.2.79) (based on LLVM 3.3svn)
Target: x86_64-apple-darwin12.5.0
Thread model: posix
on 10.15.6+ you can simply install gdb using homebrew
brew install gdb
You need to install GNU Debugger, or GDB. Try installing the full XCode package?
GDB works fine on my Mac, but then I've got full XCode installed.
Failing that, just for my peace of mind, type 'where gdb' and tell me what it prints out?
On my Mac it's in '/usr/bin/gdb', and on my linux boxes it's in '/usr/bin/gdb' and '/usr/bin/X11/gdb'.
I have just upgraded to OS X 10.8 "Mountain Lion" and I start regretting having done that.
I am no longer able to build my (simple) parallel code that uses OpenMP.
By looking here and there I understood that Apple is no more using 'gcc' but 'llvm' - quite likely due to licence-related issues. Unfortunately 'llvm' does not (yet?) support OpenMP.
I cannot believe many programs based on OpenMP will not run any more on OS X, so my question is: how can I enable OpenMP in Mountain Lion?
After reading the excellent answer of Hristo Iliev, I think I missing more than I initially thought.
I am not using XCode. The building is based on CMake and make/gcc. Yesterday I installed gcc 4.2 via macports, but - as of today - my code is still in source form because - for some strange reasons - I am not able to switch the compilation to gcc (same errors related to OpenMP).
The problem now is that CMake keeps using the llvm compiler.
In the root CMakeLists.txt I added the following two lines:
set(CMAKE_C_COMPILER "/opt/local/bin/gcc-apple-4.2")
set(CMAKE_CXX_COMPILER "/opt/local/bin/gcc-apple-4.2")
and I also added two environments variables:
export CXX=/opt/local/bin/gcc-apple-4.2
export CC=/opt/local/bin/gcc-apple-4.2
When CMake tries to find OpenMP ( FIND_PACKAGE(OpenMP) ) I get the following output:
-- The compiler is /opt/local/bin/gcc-apple-4.2
-- Try OpenMP C flag = [-fopenmp]
-- Performing Test OpenMP_FLAG_DETECTED
-- Performing Test OpenMP_FLAG_DETECTED - Failed
[...]
CMake Error at /opt/local/share/cmake-2.8/Modules/FindPackageHandleStandardArgs.cmake:97 (message):
Could NOT find OpenMP (missing: OpenMP_C_FLAGS OpenMP_CXX_FLAGS)
Call Stack (most recent call first):
/opt/local/share/cmake-2.8/Modules/FindPackageHandleStandardArgs.cmake:291 (_FPHSA_FAILURE_MESSAGE)
/opt/local/share/cmake-2.8/Modules/FindOpenMP.cmake:159 (find_package_handle_standard_args)
demo/CMakeLists.txt:8 (FIND_PACKAGE)
I tried to run /opt/local/bin/gcc-apple-4.2 manually and it fails due to a missing libgomp.
Regards
LLVM is a compiler framework that Apple uses extensively in OS X (most notably in the OpenGL implementation), not a compiler itself. There are two LLVM frontends available in Xcode - the old GCC-based one llvm-gcc (which supports OpenMP 2.5) and the new clang (which does not support OpenMP). clang has extensive static code analysis capabilities and also much nicer error reporting, especially with C++ code. Mostly that's the reason Apple is investing in it and moving away from GCC (the FreeBSD project, on the other side, is seeking to replace GCC with clang for purely license-related reasons). There is an ongoing project clomp (not to be mistaken with Intel's Cluster OpenMP) that seeks to create an OpenMP-aware version of clang, but it is far from mature.
If you do not need new OpenMP constructs like explicit tasks and can live with some bugs, you can still use the old GCC frontend. Just switch the compiler suite in the project settings to LLVM GCC 4.2:
This one is based on the really ancient GCC 4.2.1 and no longer seems to be developed. Should you need a newer version of GCC, simply build one. Unfortunately I cannot provide you with information on how to integrate it into Xcode. It works for me on the command line with GCC 4.7.1 and OS X 10.8.2 (and I don't use Xcode much).
Just adding few words to excellent Hristo's answer: you can install gcc via MacPorts. This is much simpler than compiling everything by hands (and compiling gcc from scratch might be really non-trivial task due to dependencies, etc).
So, install MacPorts, do "sudo port install gcc47", wait few hours and you'll end with gcc-mp-4.7 which is able to compile your OpenMP code.